package com.infraware.supermanbooks;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.ListFragment;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.infraware.supermanbooks.book.BookContent;
import com.infraware.supermanbooks.utils.FileExplorer;
import com.infraware.supermanbooks.utils.FileExplorer.OnFileFoundListener;

/**
 * A list fragment representing a list of Books. This fragment
 * also supports tablet devices by allowing list items to be given an
 * 'activated' state upon selection. This helps indicate which item is
 * currently being viewed in a {@link BookDetailFragment}.
 * <p>
 * Activities containing this fragment MUST implement the {@link Callbacks} interface.
 */
public class BookListFragment extends ListFragment {

    /**
     * The serialization (saved instance state) Bundle key representing the
     * activated item position. Only used on tablets.
     */
    private static final String STATE_ACTIVATED_POSITION = "activated_position";

    /**
     * The fragment's current callback object, which is notified of list item
     * clicks.
     */
    private Callbacks mCallbacks = sDummyCallbacks;

    /**
     * The current activated item position. Only used on tablets.
     */
    private int mActivatedPosition = ListView.INVALID_POSITION;

    private BookListAdapter adapter;

    private OnBookFoundListener onBookFoundListener;
    private OnNotifyDataSetChanged onNotifyDataSetChanged;
    private ProgressDialog progressDialog;
    private boolean cancelToRefresh;

    /**
     * A callback interface that all activities containing this fragment must
     * implement. This mechanism allows activities to be notified of item
     * selections.
     */
    public interface Callbacks {
        /**
         * Callback for when an item has been selected.
         */
        public void onItemSelected(String id);
    }

    /**
     * A dummy implementation of the {@link Callbacks} interface that does
     * nothing. Used only when this fragment is not attached to an activity.
     */
    private static Callbacks sDummyCallbacks = new Callbacks() {
        @Override
        public void onItemSelected(String id) {
        }
    };

    /**
     * Mandatory empty constructor for the fragment manager to instantiate the
     * fragment (e.g. upon screen orientation changes).
     */
    public BookListFragment() {
        onBookFoundListener = new OnBookFoundListener();
        onNotifyDataSetChanged = new OnNotifyDataSetChanged();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        this.adapter = new BookListAdapter(getActivity(), R.layout.fragment_book_list, android.R.id.text1, BookContent.ITEMS);
        setListAdapter(this.adapter);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // Restore the previously serialized activated item position.
        if (savedInstanceState != null && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
            setActivatedPosition(savedInstanceState.getInt(STATE_ACTIVATED_POSITION));
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        // Activities containing this fragment must implement its callbacks.
        if (!(activity instanceof Callbacks)) {
            throw new IllegalStateException("Activity must implement fragment's callbacks.");
        }

        mCallbacks = (Callbacks)activity;
    }

    @Override
    public void onDetach() {
        super.onDetach();

        // Reset the active callbacks interface to the dummy implementation.
        mCallbacks = sDummyCallbacks;
    }

    @Override
    public void onListItemClick(ListView listView, View view, int position, long id) {
        super.onListItemClick(listView, view, position, id);

        // Notify the active callbacks interface (the activity, if the
        // fragment is attached to one) that an item has been selected.
        mCallbacks.onItemSelected(BookContent.ITEMS.get(position).id);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (mActivatedPosition != ListView.INVALID_POSITION) {
            // Serialize and persist the activated item position.
            outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
        }
    }

    /**
     * Turns on activate-on-click mode. When this mode is on, list items will be
     * given the 'activated' state when touched.
     */
    public void setActivateOnItemClick(boolean activateOnItemClick) {
        // When setting CHOICE_MODE_SINGLE, ListView will automatically
        // give items the 'activated' state when touched.
        getListView().setChoiceMode(activateOnItemClick ? ListView.CHOICE_MODE_SINGLE : ListView.CHOICE_MODE_NONE);
    }

    private void setActivatedPosition(int position) {
        if (position == ListView.INVALID_POSITION) {
            getListView().setItemChecked(mActivatedPosition, false);
        } else {
            getListView().setItemChecked(position, true);
        }

        mActivatedPosition = position;
    }

    public void refresh() {
        cancelToRefresh = false;

        FileExplorer explorer = new FileExplorer(onBookFoundListener);

        String sdcard = Environment.getExternalStorageState();
        if (sdcard.equals(Environment.MEDIA_MOUNTED)) {
            // Search the external storage
            explorer.getFiles(Environment.getExternalStorageDirectory().getAbsolutePath(), "epub");
        } else {
            // Search the internal storage        
            explorer.getFiles(Environment.getRootDirectory().getAbsolutePath(), "epub");
        }

        adapter.clear();

        showProgressDialog();
    }

    private void showProgressDialog() {
        progressDialog = new ProgressDialog(getActivity(), android.R.style.Theme_Dialog);
        progressDialog.setOnCancelListener(new OnCancelListener() {

            @Override
            public void onCancel(DialogInterface dialog) {
                cancelToRefresh = true;
            }
        });

        progressDialog.show();
    }

    private void dismissProgressDialog() {
        if (progressDialog != null) {
            progressDialog.dismiss();
        }
    }

    private class OnBookFoundListener implements OnFileFoundListener {
        private final String TAG = "OnBookFoundListener";

        @Override
        public boolean onFound(String path) {
            // this method is called in AsyncTask thread.
            Log.d(TAG, "[onFound] " + path);

            synchronized (adapter) {
                adapter.add(path);
            }
            getActivity().runOnUiThread(onNotifyDataSetChanged);
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            return !cancelToRefresh;
        }

        @Override
        public void onDone(int foundCount) {
            // this method is called in UI thread
            Log.d(TAG, "[onDone] found : " + foundCount);
            Toast.makeText(getActivity(), foundCount + " Books were found.", Toast.LENGTH_SHORT).show();
            dismissProgressDialog();
        }
    }

    private class OnNotifyDataSetChanged implements Runnable {

        @Override
        public void run() {
            synchronized (adapter) {
                adapter.notifyDataSetChanged();
            }
        }

    }

}
